Contribution of regional 3D meniscus and cartilage morphometry by MRI to joint space width in fixed flexion knee radiography—A between-knee comparison in subjects with unilateral joint space narrowing

• Published in: European journal of radiology Vol. 82; no. 12; pp. e832 - e839
• Main Authors: Bloecker, K., Wirth, W., Hunter, D.J., Duryea, J., Guermazi, A., Kwoh, C.K., Resch, H., Eckstein, F.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.12.2013
• Subjects: 3D MRI quantitative imaging; Aged; Arthrography - methods; Cartilage morphometry; Cartilage, Articular - diagnostic imaging; Cartilage, Articular - pathology; Female; Fixed flexion knee radiography; Humans; Imaging, Three-Dimensional - methods; Joint space width; Magnetic Resonance Imaging - methods; Male; Menisci, Tibial - diagnostic imaging; Menisci, Tibial - pathology; Meniscus morphometry; Middle Aged; Osteoarthritis, Knee - diagnosis; Patient Positioning - methods; Radiology; Range of Motion, Articular; Reproducibility of Results; Sensitivity and Specificity; Joint space width; Meniscus morphometry; Cartilage morphometry; Fixed flexion knee radiography; 3D MRI quantitative imaging
• ISSN: 0720-048X; 1872-7727; 1872-7727
• DOI: 10.1016/j.ejrad.2013.08.041

Radiographic joint space width (JSW) is considered the reference standard for demonstrating structural therapeutic benefits in knee osteoarthritis. Our objective was to determine the proportion by which 3D (regional) meniscus and cartilage measures explain between-knee differences of JSW in the fixed flexion radiographs. Segmentation of the medial meniscus and tibial and femoral cartilage was performed in double echo steady state (DESS) images. Quantitative measures of meniscus size and position, femorotibial cartilage thickness, and radiographic JSW (minimum, and fixed locations) were compared between both knees of 60 participants of the Osteoarthritis Initiative, with strictly unilateral medial joint space narrowing (JSN). Statistical analyses (between-knee, within-person comparison) were performed using regression analysis. A strong relationship with side-differences in minimum and a central fixed location JSW was observed for percent tibial plateau coverage by the meniscus (r=.59 and .47; p<.01) and central femoral cartilage thickness (r=.69 and .75; p<.01); other meniscus and cartilage measures displayed lower coefficients. The correlation of central femoral cartilage thickness with JSW (but not that of meniscus measures) was greater (r=.78 and .85; p<.01) when excluding knees with non-optimal alignment between the tibia and X-ray beam. 3D measures of meniscus and cartilage provide significant, independent information in explaining side-differences in radiographic JSW in fixed flexion radiographs. Tibial coverage by the meniscus and central femoral cartilage explained two thirds of the variability in minimum and fixed location JSW. JSW provides a better representation of (central) femorotibial cartilage thickness, when optimal positioning of the fixed flexion radiographs is achieved.